obama also praised preacher jeremiah wright, calling him a great leader and trusted friend. the obama campaign released this overnight, in a transparent attempt to change the subject from his comments attacking half of the american people, mitt romney's allies recirculated a video of a 2007 event that was open to and extensively covered by the press at the time, end quote. the romney campaign denies having anything to do with that tape. >>> this is unfolding as the candidates prepare to take the stage tonight in denver. >> 50 million viewers are expected to tune in as the presidential racets final week. abc's brandi hitt has a preview. >> reporter: both candidates took a break from their intense debate prep tuesday. with mitt romney getting a bite to eat in denver. and president obama visiting the hoover dam for the first time. both have relied heavily on their running mates this week to lead their campaigns. >> how they can justify raising taxes on the middle-class has been varied the last four years. >> reporter: it didn't take long for paul ryan to pounce on that comment.